1. Field of the Invention
The present invention relates to a wiring pattern formation method, a manufacturing method for a multi layer wiring substrate, and an electronic device.
Priority is claimed on Japanese Patent Application No. 2004-282217, filed Sep. 28, 2004, the content of which is incorporated herein by reference.
2. Description of Related Art
In the manufacture of wiring or the like which is incorporated in an electronic circuit of an integrated circuit, for example, a lithographic method may be used. In such a lithographic method, there is a requirement for large scale equipment such as a vacuum device and complicated processing. Furthermore, with a lithographic method, the cost of manufacturing is high, since the efficiency of utilization of material is only around a few percent, and it is not possible to avoid throwing away almost all of this material. In this connection, as a process to be utilized instead of such a lithographic method, there has been investigated a method of directly patterning a liquid containing functional material upon a substrate using an ink jet apparatus (a so-called liquid drop ejection method). For example, in U.S. Pat. No. 5,132,248, there is proposed a direct patterning method, in which a liquid in which minute electrically conducting particles are dispersed is coated upon a substrate by a liquid drop ejection method, and in which this coated pattern is subsequently converted into an electroconductive layer pattern by performing heat processing and laser irradiation. Furthermore, in Japanese Unexamined Patent Application, First Publication 2004-241514, there is proposed a method of forming a multi layer circuit substrate by forming, in order, an electrically conductive pattern and an insulating pattern by a liquid drop ejection method. Yet further, Japanese Unexamined Patent Application, First Publication 2004-200563, there is proposed a method of forming, with a liquid drop ejection method, an insulating layer embedded between one wiring line and another.
Recently, the increase of the density of the circuitry incorporated in devices has progressed remarkably, and thus, for example, there are incessant demands for making wiring patterns yet smaller and finer. However, when attempts are made to form such very fine wiring patterns by a liquid drop method of the type described above, difficulties arise in forming these fine wiring patterns accurately and stably, since, after striking the substrate, the liquid drops which are ejected tend to wet the substrate and spread out over it.